Control of electric switches



Dec. 15, 1931- F. T. COLDWELL CONTROL OF ELECTRIC SWITCHES OriginalFiled April 27, 192'? 2 Sheets-Sheet N M s 4 w ML P w c c. .1

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b4 8 a. v3? e f 3 L 30 I 000 lllll Inventor Frank T. ColdweH, 193 M I AHis Attorngy.

Patented Dec. 15, 1931 2 UNITED STATES PATENT OFFICE FRANK '1. COLDWELL,OI ALPLAUS, NEW YORK, ASSIGNOR '10 GEN ERAL ELECTRIC COM-' PANY, A.CORPORATION OF NEW YORK CONTROL OF ELECTRIC SWITCHES Application filedApril 27, 1927, Serial My invention relates to improvements in thecontrol of electric switches and particularly circuit breakers. Anobject of my invention is to provide improved control apparatus suchthat there is always available until the next operation a definiteindication of the last operation whether performed autbmatically ormanually. Another object of my invention is to provide improved controlapparatus such that a circuit breaker cannot be maintained closed underthe conditions for which it is intended to be open.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope will be pointed out in the appended claims.

In the accompanying drawings, Fig. 1 illustrates in perspective acontrol switch embodying my invention, Fig. 2 illustratesdiagrammatically an embodiment of my invention in a circuit breakercontrol compris- .ing the switch shown in Fig. 1, Figs. 3 a to finclusive illustrate diagrammatically the different contact controllingpositions of the switch shown in Fig. 1 as applied to the circuitbreaker control shown in Fig. 2, Fig. 4 illustrates diagrammaticallyanother embodiment of my invention in a circuit breaker controlcomprising the switch shown in Fig. 1, and Figs. 5 a to f inclusiveillustrate diagrammatically the different contact controlling positionsof the switch shown in Fig. 1 as applied to the circuit breaker controlshown 1n Fig. 4.

The control switch shown in Fig. 1 comprises an operating member, suchas a shaft 10, arranged for both rotary and translatory movements, arotatable member or contact controlling element which may be a sleeve 11concentric with and rotatable on the shaft 10 and means mechanicallyinterconnecting them so that the sleeve can be rotated only on thetranslation of the shaft after a predetermined angular movement thereof.

The shaft 10 is mounted for both the rotary and lengthwise movements inbearing plates 12, 13 which may be suitably secured to a base late 14 soas to form a part of'the switch rame. A tie plate 15 which may also No.187,080. Renewed July 24, 1931.

serve as a terminal and contact supporting member and is then preferablyof insulating material, is secured to the bearing plates 12 and 13. Forsecuring the switch to a panel, suitable fastening means such as screws16 may be passed through an escutcheon plate 17 on one side of thepanel, not shown, and through the panel into the bearing plate 13 on theother side of the panel. The shaft 10, which is also arranged to projectthrough the panel, is biased for lengthwise movement in a mounted on theplate 15 and while the arms 20,

21 are shown as a single member they may be separate. Also secured tothe shaft 10 is an operating handle or knob 26 on which, in order toaccentuate the angular position of the shaft, I prefer-to mount a stripof material 27 so contrasting with the color of the handle as to beeasily distinguishable at a distance. With the handle oval shaped asshown, this gives not only a shape but also a color distinction as tothe position of the handle.

The sleeve 11 by its rotation is arranged to control a plurality ofcontacts 28 to inclusive which are mounted on the plate 15. For thispurpose and in order to secure a predetermined sequence in theoperation, the sleeve may comprise one or more cams 36 Whose contour asshown' is that of a circle minus a segment thereof. These cams 36 arearranged to actuate contact supporting members 37 which carry bridgingcontacts and which as shown are guided by the contacts and by centralstems 38 which project through holes in the plate 15 and a bearing strip39.

The supporting members 37 are biased towards their respective cams bysuitable means such as springs 40 and by reason of the holes for thestems 38 being somewhat larger than the stems a tilting action occurs oncontact opening so that a wiping action is obtained. Inthe switchillustrated the cams 36 are so arranged that the pairs of contactsincluding 28 to 33 are open when the contacts 34, .35 are closed andvice-versa, an angular movement of 90 in the direction indicated by thearrow 25 or the reverse rotation serving to shift from either to theother. The interconnecting means for effecting rotation of the sleeve 11on rotation of the shaft 10 followed by lengthwise movement thereof in adirection opposite that indicated by the arrow 18 comprises as shown acrank 41 secured to the shaft 10 and carryin a crank pin 42, a crank 43rotatably mounte on the shaft 10 but reciprocable therewith and vcarrying a crank pin 44, a resilient connection such as a tension spring45 between the cranks 41 and 43,-a crank 46 secured to the sleeve 11 andarranged to be engaged by the crank pin 44 and an interlock plate 47mounted on the plate 15 and provided with holes in the path of movementof the crank pin 44.

The crank 41 as shown is arranged to permit a substantially 90 movementof the shaft 10 in the direction indicated by the arrow 25 and reverse.For this purpose and so that the shaft 10 cannot be rotated after it hasbeen moved lengthwise a predetermined amount in a direction oppositethat indicated by the arrow 18, the crank 41 is provided with slots 48,49 the extreme sides of which are long enough to engage the lowerportion of a stop 50 mounted on the base plate 14. These slots arearranged to receive the higher portion of the stop 50 when the shaft 10is retracted a predetermined amount. Thus in the switch position shownin Fig. 1, the shaft 10 can be rotated substantially 90 in the directionindicated by the arrow 25 until the longer side of the slot 49 enga esthe lower portion of the stop 50 if the sha t is not retracted farenough to have both sides of the slot 49 engage the higher portion ofthe stop 50. This latter interlock occurs before the shaft 10 can beretracted sufliciently to close contacts 22, 23 or 23, 24. The torsionspring 45 is supported on the hub of the crank 43 and is ar ranged so tobias the cranks 41 and 43 and,

therefore, the crank 46 that they tend to assume the same angularosition. For this purpose the free ends of the spring 45 are arranged onopposite sides of the crank pins 42 and 44 with enough initial bias tohold the crank 41 with the longer side of one of the slots 48, 49against the lower portion of the stop 50. The crank pin 44 althoughrlgidly secured to the crank 43 is movable lengthwise in its opening inthe crank 46 and the holes in the plate 47. In order to reduce thefriction between the cranks 43 and 46, they may be spaced by washers onthe shaft 10 and a separator plate 51 secured to the base plate 14. Thewasher 52 between the plates 51 and the crank 43 is suitably secured tothe shaft 10 so that on retraction thereof the crank moves with theshaft. Also in order to prevent overtravel of the sleeve 11 stops 53arranged in the path of movement of the sleeve crank 46 may be provided.

With the switch parts positioned as shown ,in Fig. 1 only the contacts34 and 35 are bridged or closed. If the shaft 10 is retracted by pullingoutwardly on the handle 26 against the bias of the spring 19, the shaftcannot be turned since the slot 48 in the crank 41 will engage thehigher portion of the stop 50. If the shaft 10 is retracted sufficientlythe contacts 22, 23 may be bridged by the arm 20, but no change willoccur in the contacts controlled by the rotation of the sleeve 11. If,however, the shaft 10 instead of being retracted is rotated by turningthe handle in the direction indicated by the arrow 25, energy will bestored in the spring 45 and the rotation will cease when the long sideof the slot 49 engages the lower portion of the stop 50. The shaft 10and, therefore, the crank 43 may now be retracted sufficiently to drawthe crank pin 44 out of the hole in one side of the plate 47. In thisretractive movement of the shaft 10, the contacts 23, 24 are bridged bythe arm 21 prior to the release of the crank pin 44, the contacts 22, 23and 24 being so mounted as to allow further retractive movement of theshaft after they are engaged by their respective circuit controllingarms. On the release of the crank pin 44 from the plate 47', the cranks43 and 46 and, therefore, the sleeve 11 will under the bias of thespring 45 be quickly rotated in the direction indicat'ed by the arrow 25until the crank pin 44 registers with the hole in the other side of theplate 47 Now when the handle 26 is released, the shaft 10 and thereforethe crank pin 44 will under the bias of the spring 19 becounter-actuated or moved in the direction indicated by the arrow 18 andconsequently the crank pin 44 will pass through the registering hole inthe plate 47, thus locking the sleeve 11 against rotation. The rotationof the sleeve 11 effected by the energy stored in the spring 45 causesthe opening of the contacts 34, 35 and the closing of the contact pairscomprising contacts 28 to 33 inclusive. The handle 26 and the strip 27are now vertical and will so remain until the handle is turned in adirection opposite that indicated by the arrow 25 and then retractedsufficiently to release the crank pin 44 from its hole in the plate 47.In this reversed rotation and subsequent retraction, the contacts 22 and23 are bridged by the circuit controlling arm 20 and the contacts 28 to35 inclusive restored to the condition shown in Fig. 1 with the handle26 and strip 27 horizontal- This operation will be obviousfrom thepreceding.

In Figs. 2 and 4, I have illustrated embodiments of my invention asapplied to a latched closed type of circuit breaker 54 which is arrangedto control a circuit 55 and which is provided with suitable opening andclosing means. These are s own as comprising trip and closing coils 56and 57 respectively. The circuit of the trip coil 56 may be controlledby means responsive to a condition of the circuit 55 such as anover-current relay 58 which is arranged to be energized in accordancewith the current in a conductor of the circuit in any suitable manner asby a current transformer 59 in the case of an alternating currentcircuit. The circuit breaker is also provided with auxiliary switchescomprising contacts. 60 and 61 which are arranged to be closed when thecircuit breaker is open and vice-versa and contacts 62 which arearranged to be closed when the circuit breaker is closed and open whenit is open. Since the closing coil 57 may require a relatively largecurrent, it is frequently preferable to control its circuit through acontrol relay 63 which is provided with contacts suitable for thepurpose and which is of the instantaneous closing time delay openingtype so as to allow time for the latching of the circuit breaker.

In order to have a visual indication of the closing of the circuitbreaker 54, there is provided a red lamp 64 whose circuit is controlledby the auxiliary switch contacts 62 and which may be in series with thetrip coil 56 to indicate a failure of the tripping circuit while thecircuit breaker is closed. In order to have a visual indication of theopening of the circuit breaker, there is provided a white lamp 65 whichis in series with the auxiliary switch contacts and may also be inseries with the winding of the control relay 63 so as to indicate afailure of the control relay circuit while the circuit breaker is open.For an audible indication of the automatic opening of the circuitbreaker 54, that is by the operation of the relay 58 for example,

there may be provided a suitable device such as a horn-66 which mayserve for one or more circuit breakers.

For controlling the opening and closing means and the indicating means,I employ in accordance with my invention a control switch such asillustrated in Fig. 1 so ar-' ranged as to provide independently of theoperator an absolute indication of the last operation performed. InFigs. 2 to 5 the control switch is illustrated schematically forsimplicity as a rectangle embracing merely the contacts 22, 23, 24 and28 to 35 inclusive together with the contact bridgin members andconnection arrangements 0 the contacts. Thus, for example, in Figs. 2,3a, 4, and 5a, the control switch is illustrated with the contacts andbridging member in the condition shown in Fig. 1.

Referring now in particular to Figs. 2 and 3 a to f inclusive, thecontacts 22 and 35 are connected by a lead 67, the contacts 23 andthereby leaving the 30 by a lead 68 and the contacts 24 and 32 by a lead69. The circuit breaker 54 is open and the circuit of the white lamp 65is completedas follows: the auxiliary switch contacts 61, the controlrelay 63, the conductor 70, the lamp 65, and the resistor 71. Theresistor 71 is so chosen that the white lamp 65 is dimly lighted whenall of the resistor is in series with the lamp. The control switchhandle 26 is horizontal, the circuit of the horn 66 is open at contacts28, 29, the

v circuit of the control relay 63 is open at the control switch contacts23, 24 and also at the contacts 32 and 33, and the circuit of the tripcoil 56 is open at the auxiliary switch contacts 62 and also at thecontrol switch contacts 22, 23.

To close the circuit breaker 54, the handle 26 is turned in thedirection of the arrow 25, Fig. 1, and pulled. The initial pull closesthe contacts 23 and 24 through the arm 21 as shown in Fig. 3b and thefinal pull effects the rotation of the sleeve 11 thereby open= ing thecontacts 34, 35 and closing the contact pairs comprising the contacts 28to 33 inclusive as shown in Fig. 30. The circuit of the control relay 63is thereby completed through the contacts 32, 33 and 23, 24. Throughthis relay and the closing coil 57 the closing of the circuit breaker isefiected. The circuit of the horn 66 is momentarily completed. Thisgives a test of the horn.

The circuit of the white lamp 65 is momentarily completed through only aportion of the resistor 71 sufiicient to permit "a more intenseillumination of the lamp. .This ives a test of the lamp. The operatlnghan le 26 is now vertical and the red lamp 64 is lighted. When thehandle is released, the arm 21 opens the contacts 23, 24 as shown inFig. 3d, circuit of the control relay 63 open in case the circuitbreaker should open.

If the circuit breaker is tripped automatically, that is by the relay58, the circuit of the red lamp 64 is broken at the auxiliary switchcontacts 62 and the circuit of the white lamp 65 is completed throughthe auxiliary switch contacts 61, the conductor 70, the lamp 65, theupper portion of the resistor 71, and the contacts 30, 31. In this casethe lamp 65 gives a more intense indication than when the circuitbreaker is tripped manually so that where several circuit breakers arecontrolled from one switchboard,i-;a mere glance at the switchboard willenablethe operator to tell which of the circuit breakers has opened.This eliminates any necessity for distinguishable audible signals forthe different circuit breakers. Consequently one audible indicator suchas the horn 66 may be used for all the circuit breakers. The'circuit ofthe horn 66 is completed through the auxiliary switch contacts 60 andthe control switch contacts 28, 29. To stop the born 66 and reduce theintensity of theflanup 65, if the circuit breaker is to reniain open,the operating handle 26 is turned oppositely to the direction indicatedby the arrow 25 in 5 Fig. 1 and pulled. The initial pull closes thecontacts 22 and 23 by the arm as shown in Fig. 3e and the final pulleffects the reverse rotation of the sleeve 11 thereby closing contacts34 and 35 and opening the contact pairs comprising the contacts 28 to 33inclusive as shown in Fig. 3f. This opens the circuit of the horn 66 atthe contacts 28, 29 and the circuit of the control relay 63 at thecontacts 32, 33 and by opening the contacts 30, 31 cuts in all of thereslstance 71 in the circuit of the white lamp 65 which thereforeproduces a less intense indication, that is like the white lamps ofother circuit breakers which may be open. The control switch handle 26is go now horizontal and when released returns to the position shown inFig. 1. When the circuit breaker 54 is tripped by the operation of thecontrol switch, the circuit of the trip coil 56 is closed at thecontacts 34, 35 and 22.

23 by operating the control switch as described above in connection withFigs. 36 and f. In this case the horn 66 is not sounded and thewhitelamp 65 instead of showing bright and dim shows dim only.

36 In the modification of my invention shown in Fig. 4, the control issuch that the operator cannot maintain the circuit breaker 54 closedunder the conditions for which it is intended to be open. For thispurpose the connections difier from those in Fig. 3 and an auxiliaryrelay 72 is so arranged that the'operator cannot hold the circuitbreaker closed or reclose the circuit breaker without first goingthrough the tripping operation.

In this case, the contacts 23 and 35 are connected by. a lead 73, thecontacts 23 and 30 by a lead 74, and the contacts 32 and 34 by a lead75. The circuit of the control relay 63 is now arranged so that it canbe completed only when the auxiliary relay 72 is energized and itscontacts 76 closed. When the control switch'parts are positioned asshown in Fig. 1 and as indicated schematicallyin Figs-4 and 5a, thecircuit of the auxiliary'relay 72 is completed when the circuit breaker54 is open as follows: auxiliary switch contacts 61,

conductor 77, resistor 78, relay 72, control switch contacts 34, 35 andleads 73 and 74. If the control switch has not been operated to thetripping position as indicated in Figs. 4 and 5a, it will of course beimpossible for the relay 72 to close its contacts -7 6, since thecontrol switch contacts 34, 35 will be open. If.

now the operating handle 26 is turned in the direction indicated by thearrow 25 in Fig. 1 and retracted, the control switch contacts 23 and 24will be closed by the arm 21, thus clos-' ing the circuit of the relay 2through its contacts 23 and 24 before the control switch contacts34 and35 are opened on the final pull of the operating handle which efiectsthe rotation of the sleeve 11. The control switch contacts are now inthe condition shown in Fig. 50 and the handle 26 is vertical. Thecircuit of the control relay 63 is completed as follows: auxiliaryswitch contacts 61, control relay 63, control switch contacts 33, 32,lead 75, auxiliary relay contacts 76, control switch contacts 24, 23 andlead 74. When the control switch handle is released, the contacts 23 and24 are opened as shown in Fig. 5d thereby opening the circuits of boththe control relay 63 and the auxiliar relay 72. Since the latter can beenergize only when the control switch contacts 34, 35 and the auxiliaryswitch contacts 61 are closed, the operating handle 26 must be turnedoppositely to the direction indicated by the arrows 25 in Fig. 1 andretracted to cause the rotation of the sleeve 11. During this operationas shown in Figs. 5 e and f, the circuit of the trip coil 56 iscompleted as follows: the auxiliary switch contacts 62, thetrip coil 56,the conductor 7 9, the control switch contacts 22, 23 and the lead 74.The control switch handle 26 when released is horizontal and the controlswitch contacts as indicated in Figs. 4 and 5a. The circuits of thelamps 64 and 65 and the horn 66 will be obvious by analogy with thosetraced in connection with the description of Fig. 2.

While I have shown and described my invention in considerable detail, Ido not desire to be limited to the exact arrangements shown, but seek tocover in the appended claims all those modifications that fall withinthe true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A switch comprising an o erating mem- 10 ber adapted to be rotated anto be moved engthwise, a rotatable contact controlling element, meansfor rotating said element arranged to have energy stored therein onrotation ofsaid member and means for pre- 11 venting rotation of theelement until the member has been rotated a predetermined amountarranged to be released on a predetermined lengthwise movement of themember in one direction. 11

2. A control switch comprising an operating shaft adapted to berotated'and to be moved lengthwise, a contact controlling sleeveconcentric with the shaft and rotatable relatively thereto, means forrotating the sleeve 11 arranged to have energy stored therein onrotation of the shaft and means for preventing the energy storing meansfrom rotating the sleeve until the shaft has been rotated apredetermined amount arranged to be re- 11 leased on a predeterminedlengthwise movement of the shaft in one direction. I

3. A switch comprising an operating member arranged for rotary andtranslatory movements, an element arranged for rotary 1 movement andmeans mechanically inter-- connecting the member and the element forefi'ecting rotation of the element only aiter the member is rotated apredetermined amount and then translated a predetermined amount in onedirection,

4. A switch comprising two rotatable concentric members one of which isarranged for translatory movement and means mechanically interconnectingthe members for eilectmg rotation of the other member only after the onemember is rotated predetermined amount and then translated apredetermined amount in one direction.

5. A control switch comprising a rotatable contact controlling elementand actuating means therefor comprising a rotatable and lengthwisemovable operating member, means for biasing said operating member forlengthwise movement in one direction and means operative on apredetermined lengthwise movement of said operating member in theopposite direction after a predetermined angular movement thereof foreffecting the rotation of said element from one contact controllingposition to another.

6. A control switch comprising a rotatable contact controlling elementand actuating means therefor comprising a rotatable and lengthwisemovable opera-ting member, means for biasing said operatin member forlengthwise movement in one irection, means operative on a predeterminedlengthwise movement of said operating member in the "oppo site directionafter a, predetermined angular movement thereof for effecting therotation of said element from one contact controlling position toanother, and contacts arranged to be controlled by said operating memberon the lengthwise movements thereof.

7. A control switch comprising a rotatable contact controlling elementand actuating means therefor comprising a rotatable and lengthwisemovable operating member, means for blasmg said operating member forlength ,wise movement in one direction, means operative on apredetermined lengthwise movement of said operating member in the oppo:

site direction after a predetermined angular movement thereof foreffecting the rotation of said element from one contact controllingposition toanother, and contacts arranged to be controlled by saidoperating member on the lengthwise movements thereof and to cooperatewith the contacts controlled by said element,

8. A switch comprising a rotatable and translatable operating member, arotatable element, and means for effecting rotation of said element onlyafter said member is rotated a predetermined amount and then translated.a predetermined amount in a given direction,

9 A switch comprising two rotatable members, one of which is arrangedfor translatory movement and means for effecting rotation of the othermember only after the one memher is rotated at predetermined amount andthen translated a predetermined amount in a given direction.

10. A switch comprising a plurality of movable contacts, a movablemember for actuating said movable contacts to one contact controllingposition, means "for producing a connter-actuation of said member tomove one of said contacts to another trolling position and means foranoth r contact of said conta s file contact controlling position towhich it was moved until a further actuation of said movable member,

11. A switch comprising plurality oi" fixed contacts, a pluralitycooperating movable contacts, a movable member for actuating saidmovable contacts to engage their respective fixed contacts, means forproducing a countenactuation of said member to disengage one of saidmovable contacts, and means for maintaining another movable contact inthe engaged position until a further actuation of said movable member,

In witness whereof, E have hereunto set my hand this 26th day oi April,1927,

FRANK T, COLDWELL.

contact con-

